Well-drilling apparatus



ZASLUQQ R. J. GILL WELL DRILLIN G APPARATUS Filed Jan. 14, 1946 Patented Sept. 6, 1949 WELL-DRILLING APPARATUS Robert J Gill, Los Angeles, Calif. Application January 14, 1946, Serial No, 641,1 18

1 Claim. 1 A

This invention relates to well drilling apparatus and is particularly'directed to. a rotary boring' device adapted tot-be lowered into a well hole. In conventional rotary drilling equipment, it is the practice to employ a string of drill pipe for turning a bit, at thebottom o f the hole. Power for rotating the drillstrin' and the bit is furdvb enpamiusl cat d at e t o the well. In the drilling of vdeep wells, much of the powerimparted to the rotating equipment at the surface i 1 s r e /at re chest b since the frictionbetween the rptatingldrill string and the well casing orbetweenthe rotating drill s rin and the well hole ab sorbs large amounts of POWEIM Furthermore, the conventional drill string on a deep well requireshigh capacity surface equipment for hoisting the drill string out of the hole when it is necessary tochange the bit; Indeed, on dec wellsit has been found from experience vthat more time is consumed inhoisting the drill pipe out of the well and re-inse rting it after replacement of the ,bitthan is spent with the b oper tin f t tto -7.

It is, e eiq t ep incipal o je tor y vention to remedmthese difficulties inherent in the conventional rotary drilling system and to provide a device which maybe lowered into a well hole as a unit and in which the power for rotating the bit is derived from a source near the bottom of the hole..

Another object of this invention is to provide Well boring apparatus in which'thepower means for rotating the bit is located in the well bore adjacent to the bit and wherein additional means are provided for applying axial pressure to the l Another object is to provide a device of this type which employs a feed 'down mechanism which is adapted it engage the side wall or the well hole.

Another object is to provide a well boring device which may be lowered'into a well hole as a unit 'andwhich' embodies independent power means for rotating the bit and for driving a feed s w m ch nism.

Other objects and advantages will appear here-1 inafte r.

In thedrawings;

riguresiyz; and 3 show longitudinal views,

partly in section, of adjoiningportions of a pref erred embodimentp'f jmy invention, The views are 7 separated into three figures for purpose of illustration,

ifiiif a i ae stse ctional view, t k r;

iii; v

2 substantially on the line 4%4 as shown in Figure 1.

Figure 5 is a transverse sectional view taken substantially on the line 5-5 as'shown in Figure2. H

Referring to the drawings, a housing generally designated I0 is adapted to'b'e lowered into a well borell. In the lower endofth'e housing to "and 'mounted co-axially 'therh'ffis spindle i2 rotatably "mounted upon bearings 13 ans M which are adapted to" absorb 'hiith" "radial" and thrust loads. A conventional welldrilling'bit i5 is removably secured to'th'elower end of the spindlen'by' meanso'f' threads [6Q "Thespi'ndle H! has an axial'passagei'l 'iorcbnveying afiu i'd t0 the bit'ii' This fli'iid'sert'esto cobl the bit 15 as well as to carrythe cuttings fro'm'th'e bit upwardly through the well holeTl' to the surface. Meanswithinthe housing It are provided for rotating the bit l5',"ahd"as"showri"in the drawin'gs this means includes the high speed electric motor 1'8 mounted in the annulus I 9 between the housing "land the spindle 12. The motor [8 is relativelyflong and relatively small in diameter but otherwise may be of conventional construe tion and mayi'nclude the usual field windings 20, the armature 2| ,an'd the'commutator assembly Means are provided for absorbing the torque reaction of the motor [8 for preventing rotation of the housing l0. As shownin the drawings, this means includes a plurality of vfeed wheels 2%, 24, and which are adapted to project outwardly through openings 21 in the housing It to engage the side wall of the wellhole II,

A relatively slow speed electricmotor 2 8 which is similar in manyrespects tolthe high speed motor I8 is mounted within the-housing l0 above the motor 18. The arm-ature zlof this slow speed motor 28 .is secured to a hollow shaft ,30 which extends axially of the housing lm Radial-thrust bearings 3! and 32 are provided for rotatably sup porting the hollowshaft 3ll within the housing I 0. A conduit 33 extends axially through the hollow shaft and is connected at'itsvlow'er end to a coupling 34. Thelower end 'of the coupling 34 encircles the upper end'of thespindle l2 to define a packing annulus ,forfthe'packing' assembly 35. This packing 'assembly35 ,forms a rotary seal between the rotatable spindle I'Zandthe non-rotat able conduit 33.,- 'Sealing means are also provided between the hollow shaft3l1 I, I and, as shown, this'frnean's includes a plurality of resilient collars 36;i0r .e'd int v v conduit3'3 iandlextehdi. 4 -d1 uybutwardlyto contact the bore 31 of the hollow shaft 30. The commutator assembly 22 for the high speed motor l8, as well as the commutator assembly 36 of the slow speed motor 28, are connected to electrical leads 39 and 40. These electrical leads 39 and 40 are embedded within the wall 4| of the conduit 33 and emerge from the conduit 33 at the lower end thereof for connection to the said commutator assemblies.

Positioned above the bearing 32 and mounted in the annulus between the housing It! and the hollow shaft 30 is a packing assembly 42. Similarly a packing assembly 43 is positioned at the lower end of the housing In between the housing and spindle l2. It will be noted that the motors l8 and 28 are mounted between the packing assemblies 42 and 43 and, therefore, operate in an oil bath enclosure which is sealed against entrance of foreign matter. In order to equalize the pressure of the fluid within the well hole II with the oil within the enclosure occupied by the motors I8 and 28, a cylindrical membrane 44 is mounted within the housing l and is secured therein by means of axially spaced bands 45. Intermediate the length of this membrane 44 is located a series of ports 46 in the wall of the housing l0. Pressure from the well hole acts against the flexible membrane 44 to equalize the pressure on the interior and exterior of the housing l0, thereby minimizing the flow of well fluid inwards through the packing assemblies 42 and 43.

Means are provided for rotating the feed wheels 23, 24, 25, and 26 and for projecting them laterally into engagement with the side wall of the well hole ll. As shown in the drawings, this means includes a pair of drive shafts 41 and 48 which are rotatably mounted within the housing H] by means of bearings 49. The shaft 41 is driven through universal joints 50 from a stub shaft mounted in bearings 52. A gear 53 on the shaft 5| carried by the bearing 52 is adapted to mesh with a gear 54 fixed on the upper end of the hollow shaft 30. Similarly the drive shaft 48 is driven through universal joints 55 and 56 and the intermediate shaft 51. The gear 59 is secured on the stub shaft 58 which is carried in the bearing 60. Secured on the drive shaft 41 are pinions 6| and 62 adapted to mesh with the gear rings 63 and 64 formed on the feed wheels 25 and 24, respectively. The shape of the gear teeth provided on the pinions 6|, Gla, 62 and 62a and the ring gears 63, 26a, 64 and 23a, respectively is such that the meshing action between each pinion and its respective ring gear operates with best efficiency when the feed wheels are in the wall engaging position. Sufficient clearance is provided between the individual teeth of the pinion and the teeth of the ring gear to permit satisfactory operation regardless of the lateral position of the feed wheel. Thus, rotation of the drive shaft 4'! in the direction indicated by the arrow 65 serves first to move the feed wheels 25 and 24 laterally outwardly into wall engaging position. Continued rotation of the shaft 41 and pinions 6| and 62 then serves to rotate the feed wheels 25 and 24 since further outward lateral movement is prevented by the contactbetween the periphery 69 of the feed wheels and the side wall of the well hole I l. Each of the feed wheels is provided with a central trunnion 66 rotatably mounted in a carrier 61. The carrier 61 is slidably mounted between the stationary projecting arms 68 fixed to the casing H]. A key 69a is provided between arm 68 and the carrier 61. Pump driven by shaft 48 delivers fluid under pressure through piping 16 to a pressure chamber I1 in each of the carriers 61 to assist in advancing each of the feed wheels toward the wall of hole I l. The periphery 69 of the feed wheels may be notched, as shown, for development of maximum tractive efiort against the side wall of the well hole II. It will be noted from the consideration of Figure 1 that the feed wheels 23, 24, and 26 extend radially outwardly in four directions, thereby maintaining the housing l0 co-axial of the well hole II. It will be understood that a greater or lesser number of feed wheels may be employed if desired.

The conduit 33 emerges from the upper end of the hollow shaft 36 and is reduced in diameter for that portion of its length between the hollow shaft and the supporting collar 10 at the upper end of the housing In. The supporting collar 10 has a central cylindrical portion H encircling a portion 12 of the conduit 33. Collars 13 are provided on the conduit 33 both above and below the cylindrical section II to provide a securing means between the conduit 33 and the housing 10.

In operation, the device is lowered into the well hole I l as a unit suspended on the lower end of a hose [4. This hose is attached integrally to the conduit 33 of the cylindrical section 12. The hose l4 carries a coolant to the bit l5 by way of the conduit 33 and the axial passageway i1 and the spindle l2. When the bit l5 comes to rest on bottom, fluid is delivered through the hose l4 and electrical energy is transmitted to the motors l8 and 28 through the electrical leads 39 and 43 embedded in the wall of the hose l4 and conduit 33. Control means (not shown) are provided at the surface for varying the speed of rotation of the motors. Rotation of the slow speed motor 28 serves to advance each of the feed Wheels 23, 24, 25 and 26 outwardly into engagement with the side wall of the well hole I l and to rotate the feed wheels for applying axial pressure to the bit l5. The speed of rotation of the motors l8 and 28 is independently variable so that the speed of the bit rotation and the speed of movement of the feed wheels are not inter-dependent but may be varied to meet changing drilling conditions.

When the bit I5 has become dull and it is necessary to replace it, the slow speed motor 28 is reversed in order to retract the feed wheels inwardly away from the side wall of the well hole H. The device is then withdrawn from the well hole H as a unit by means of the hose 14. This hose may be sectional in character and provided with couplings, not shown, at intervals throughout its length. These couplings are disengaged at the surface as the hose 14 is withdrawn from the well hole. Since no drill pipe is employed, the total weight of the assembly being withdrawn from the well hole is relatively small and hence the withdrawal of the entire unit for bit replacement may be speedily accomplished without employing the conventional heavy duty hoisting machinery.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claim.

I claim:

In a well boring device, the combination of a housing adapted to be lowered into a well bore, the housing having a plurality of circumferentially spaced windows; a spindle rotatablyv mount- 75 ed coaxially of the housing and extending through the lower end thereof; means preventing relative axial movement of the spindle and housing; a bit fixed on the lower end of the spindle; power means in the housing adapted to rotate the spindle and bit; means for preventing contrarotation of the housing, said means including a plurality of rotatable feed wheels aligned with said housing windows; bearing means for said feed wheels slidably mounted within the housing; power means for moving the bearing means to advance the feed wheels outwardly through said windows into engagement with the side wall of the well bore; and means in the housing for turning the rotatable feed wheels in side wall contacting position to apply axial pressure to said 15 bit.

ROBERT J. GILL.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,090,919 Kitsee Mar. 24, 1914 1,406,348 Corrigan Feb. 14, 1922 10 1,668,034 Zaluski May 1, 1928 1,906,771 Sandstone May 2, 1933 FOREIGN PATENTS Number Country Date 317,917 Germany Jan. 6, 1920 

